Call me what you like.
More often than not I'll stay at a fight if there's good action until I run out of bullets, gas or both.
Landing kills isn't that big a deal with me. Shooting planes down is why I play. If I thought I could land 5 if I left immediately but I might get one more good engagement by staying and then running out of gas, I'd stay. No question. I get unlimited cartoon planes for $15/mo; how about you?
Generally, I think we all know when we've made the kill, despite the mechanics of the game's kill scoring system.
For example, as someone mentioned, if you get in a fight with an opponent that has some advantage (energy, maneuverability, etc.). You go round and round for 5 minutes and you gain the upper hand; you've bled his E and you're on his six and just as you squeeze the trigger... some friendly zooms past you and gets a cockpit shot.
Who REALLY made that kill? I think we all know the true answer although the game score system may award it to the cherry picker.